Self adjusting caster



Dec. 1, 1931. P. T. HARPINE ET AL 1,834,617

SELF ADJUSTING CASTER Filed Nov. 8, 1930 Q I O l a f;

I wvamtocd /z'lz' Zlzvyz'ne wad/two 6290254 W 500 er Wide-M Patented Dec. 1, 1931 UNITED STATES PATENT OFFICE PHILIP r. HARPINE AND GEORGE w. coornn, or WASHINGTON, DISTRICT or COLUMBIA- SELF ADJUSTING CAST'FJR Application filed November 8, 1930. Serial No. 484,380.

The invention relates to self-adjusting casters of the general type embodying compression springs which, While normally inactive, serve to lower any caster or casters under which the floor may be low, and it is the object of the invention to provide a device of this character which is exceptionally simple and inexpensive, may therefore be manufactured and marketed at minimum cost, and

may be quickly and easily substituted for the conventional casters commonly used on furniture.

With the foregoing in View, the invention resides in the novel subject matter hereinafter described and claimed, description being accomplished by reference to the accompanying drawings.

Fig. 1 is a perspective View showing a plurality of the casters applied.

Fig. 2 is a vertical sectional view showing the relation of elements when the floor is level.

Fig. 8 is a vertical sectional view on line 3-3 of Fig. 2, but showing the manner in which the spring lowers the caster when the latter encounters a low portion of the floor.

Fig. 1 is a perspective view of a blank used in the preferred form of construction.

An article of furniture F is shown, whose legs L are provided with the improved casters C, and as all of these casters are duplicates, a detailed showing and description of one will suflice.

The numeral 5 denotes avertical shank for reception within the conventional spring sleeve 6 within the caster socket 7 of the leg L, the upper end of said shank being provided with a head 8 to prevent accidental dropping of the caster from thesocket. Near its lower end, the shank 5 is provided with a circumferential downwardly facing shoulder 9, said shoulder performing a function hereinafter described. The lower extremity of the shank 5 is rigidly and centrally secured at 10 to a floor-supported member 11, said member being preferably in the form of a cup provided with any preferred floor-engaging means. In the present showing, the cup 11 is downwardly stamped from the central portion of a blank 12, and the end portions 13 of this blank are bent downwardly for connection with a roller 14 in the usual way.

Telescoped with the cup 11, is an inverted cup 15 having a central opening 16 through which the lower portion of the shank 5 passes slidably, said inverted cup 15 being adapted to constantly bearupon the lowerend of the leg L,'or more correctly, against the conventional flange 17 on the lower end of the sleeve 6. Within the two cups 11 and 15 and surrounding the shank 5, is a coiled compression spring 18.

Under normal circumstances, the parts occupy the relative positions shown in Fig. 2, the upper edge of the cup 11 being in contact with the flange l7, and the cup 15 being in contact with said flange and with the bottom of said cup 11, thespring 18 being then compressed and idle. If the caster be in engagement with a low portion of the floor however, the spring 18. will downwardly move the parts 11, 5, 12, 13 and 14 to hold the latter engaged with. the lowlfloor portion, as shown at the right frontcorner of Fig. 1 and in Fig. 8.

The elements 5, 11, 15, 18, 1 1, etc. constitute a single unit adapted to be marketed as such, the shoulder 9 of the shank 5 preventing excessive movement of the cup 15 under the influence of the spring 18, prior to use of said unit. In order to install this unit, it is only necessary to force the shank 5 into the conventional sleeve 6, so that no difliculty is encountered.

While the present disclosure illustrates the preferred construction, it is to be understood that variations may be made. For instance, while in the construction illustrated, the upper edge of cup 11 strikes the flange 17 and the lower edge of cup 15 strikes the bottom of cup 11 under ordinary circumstances, it will be understood that the proportion of parts could be such that the upper edge of cup 11 would strike the flange 17 without the lower edge of cup 15 striking the bottom of said cup 11, or that the lower edge of said cup 15 could strike the bottom of cup 11 without the upper edgeof the latter striking the flange 17. As such structures however would be clear from the present disclosure, they are not illustrated.

We claim 1. In a caster, a vertical shank for slidable reception in the usual caster socket of a furniture leg, a floor-supported member secured rigidly to the lower end of said shank and having an upwardly presented facearound said shank, an inverted cup having-n cent al 0 aenin throrm'h which said shank gasses slidably, the side Wall of said cup being directiy over said upwardly presented face i-n position to abut the latter, and a compression spring surrounding said shank within said inverted cup and bearing at its ends against the latter and said upwardly presented face, said inverted cup being adapted to permanently contact with the lower endwof the afo eaentioned caster socket and with said upwardly. presented face, Whenthespring is compressed, said spring being adapted to shift the floor-supported member :and shank downwardlyp 2. in a caster a vertical shankifor slidable receptionin the-nsualcaster socket of ,a furniture leg, anupwardly open floor-supported cup. to the bottom ofwvhich said shank is rigidly and centrally secured, an annularv membe slidabie the shank and adapted to abut the lower end ofethe aforementioned caster sock t, and a. compression springv surround: said shankand'bearing againstisai'd annular nernber and the cup bottom, the side Wall of said cup beingedisposed:around .said annular member and being .oizsuiiicient height to strike the lower end of the castersocket to, limit compression of said sprin cures. 1

f PHILIP 'T. I-I'ARPINE; V GEORGE W1 coornn. 

